The invention to which this application relates is to a valve assembly. Particularly, although not necessarily exclusively the invention relates to an improvement to the type of valve known as a double block and bleed valve in which typically three independent valve units are provided within a valve body.
The provision of double block and bleed valves is well known in the industry and the applicant has several granted patents in this field. One common problem, which is experienced with this form of valve, is the requirement to fit the valve assembly into the space, which is available between adjacent pipe flanges. For larger diameter pipelines in particular the length of the conventional double block and bleed valve assembly can be greater than the ANSI B16.10 specified space. This means that if, for example, the conventional double block and bleed valve is being used to replace a single valve in an existing pipeline, the space available is too small. This therefore means that additional works are required to be performed on the pipeline, which can lead to additional time and expense being incurred.
A further problem is that the conventional double block and bleed valve assembly includes a significant number of components, which add to the complexity of the assembly process and the time for assembly.